Apparatus for repairing a pipeline and method for using same

ABSTRACT

A pipe repair apparatus includes an outer carrier tube, an inner bladder tube within the carrier tube, and a repair sleeve within the bladder tube. The bladder tube and the carrier tube are formed by one unitary tube which is folded back upon itself. A wick extends from the repair sleeve to the rear end of the bladder tube and permits evacuation of gases from the bladder tube when the bladder tube is flattened by a vacuum during insertion of a curable resin into the bladder tube at its forward end. The bladder tube can be inverted out of the carrier tube so as to place the repair sleeve in contact with an area to be repaired within a sewer pipe. This method may also be used to repair the damaged joint between a lateral sewer line and a main sewer line.

This application is a divisional of Ser. No. 09/613,958 filed Jul. 11,2000, (U.S. Pat. No. 6,482,280); which is a divisional of applicationSer. No. 09/299,486 filed Apr. 26, 1999, (U.S. Pat. No. 6,105,619);which is a divisional of application Ser. No. 08/852,590 filed May 7,1997 (U.S. Pat. No. 6,021,815); which is a divisional of applicationSer. No. 08/622,817 filed Mar. 27, 1996 (U.S. Pat. No. 5,765,597); whichis a continuation-in-part of application Ser. No. 08/243,697 filed Aug.19, 1994 now abandoned.

BACKGROUND OF THE INVENTION

This invention relates to apparatus for repairing a pipeline and methodfor using same.

One method of repairing damaged sewer pipe is to excavate the areasurrounding the sewer pipe and replace the broken portion. This is avery expensive and labor intensive solution and is also an inconvenienceto residents living in the area and utilizing roadways overlying thearea.

Another solution is in situ relining of sewer pipes. In situ methodstypically utilize a resin coated liner which is inserted into theexisting sewer pipeline and unrolled against the sewer pipe. Theunrolled liner is held against the existing sewer pipe while the resincures to form a new pipe lining within the existing pipe.

One example of such a method is shown in U.S. Pat. No. 4,366,012 datedDec. 28, 1982. In this patent is shown a process utilizing an elongatedouter tube having an inner tube comprised of felt. Uncured resin isintroduced into the tube and is used to impregnate the felt inner tube.The two concentric tubes are then inverted into the end of the sewerpipe to be repaired and the inversion process continues until the areaof the sewer pipe needing repair has been reached by the invertingtubes. Upon inversion the impregnated felt liner is placed on theoutside of the original outer liner, and is pressed against the interiorsurface of the sewer pipe. When the resin cures a new pipe liner isprovided at the area to be repaired.

U.S. Pat. No. 4,366,012 shows a method for impregnating the inner felttube with uncured resin. The impregnation is initiated by pouring theuncured resin in one end of the two concentric tubes. A slit is made inthe outer tube approximately 12 inches from the other end of the outertube. A vacuum cup is placed over the slit and a vacuum is drawn fromthe outer tube, thereby causing flattening of the outer tube andassisting the resin to spread through the fabric liner and impregnate itfrom one end to the other. Once the resin has impregnated the entirefelt liner the vacuum is shut off and a patch is solvent welded over theslit.

There are several disadvantages to this impregnation process. The slitmakes the outer tube or bladder weaker. Furthermore the cutting of aslit and the patching of a slit are time consuming. If the removal ofthe vacuum source from the vacuum cup is not timed properly, the vacuumcup will suck up some of the resin, thereby rendering the vacuumequipment inoperable.

Another disadvantage of the method of repairing a sewer pipe shown inU.S. Pat. No. 4,366,012 is that the outer bladder and the inner felttube must be inverted into the sewer pipe beginning at a manhole locatednearest to the area to be repaired. The inverted tubes must then extendto the area to be repaired, thereby requiring a length of tube whichwill reach from the nearest manhole to the area to be repaired.

For example, if a 300 foot long liner is required, the method of U.S.Pat. No. 4,366,012 requires pouring resin at one end of the tube, movingdown the tube for approximately 50 feet, making a slit in the coating ofthe fabric liner, placing a suction cup over the slit, drawing the resinto that point, removing the vacuum, and placing a patch over the slit.Then it will be necessary to move another 50 feet down the tube andrepeat the process. This process will continue at approximately 50 footintervals until the desired location on the tube is reached.

The foregoing 50 foot intervals are necessary because it is onlypossible to draw a vacuum so far down the tube and still be effective.

Another disadvantage of the method shown in U.S. Pat. No. 4,366,012 isthat the fabric liner is coated. In some applications, it would bedesirable to utilize a liner that is not coated and instead use a linerthat is separate from the bladder.

Most of the sewer mainlines are usually located in roadways and areburied at a considerable depth. These mainlines have lateral pipes thatbranch off to houses, businesses and industries. Lateral lines areconduits for carrying waste from these houses, businesses and industriesout to the mainline sewer.

Mainline sewers are typically straight with access manholes at spacedapart positions along the length of the main sewer line. Mainline sewersare usually owned by municipalities or utility companies who utilize theservices of civil or professional engineers for the design of sewerinstallations, inspections, and final work acceptances.

Lateral sewers on the other hand are typically installed by localplumbers or home owners. It is common to find numerous bends or fittingsin a lateral sewer as well as inappropriate materials used in theoriginal construction. These lateral installations offer a greaterchallenge in repair than do the reconstruction of the straight andprofessionally designed mainline sewers.

Therefore, a primary object of the present invention is the provision ofan improved apparatus for repairing a pipeline and method for usingsame.

It is another object of the present invention to provide an apparatusfor the insertion and installation of a new liner into an existing pipewhich is particularly suitable for the spot repair of damaged sectionsof a given pipeline, wherein the liner is introduced into the existingpipe by means of a carrier which encloses the liner and protects it fromcontact with the surrounding pipe walls until the liner is in itsdesired location within the existing pipe.

It is a further object of the present invention to provide a method forrelining pipes in which the pipe liner is secured to an inflationbladder, impregnated with resin and encapsulated within a positioningelement, the positioning element then being inserted into an existingpipe and fluid being introduced under pressure into the positioningelement to cause the inflation bladder and the liner secured thereto toinvert outwardly from within the positioning element to a placementposition near the compromised pipe section, the inflation bladderexpanding radially in response to fluid pressure and urging the linerinto contact against the pipe wall, and subsequently removing theinflation bladder and positioning the element from the pipe.

A further object of the present invention is the provision of animproved method for impregnating a resin absorbent material with anuncured resin while the resin absorbent material is within an inflatablebladder tube.

A further object of the present invention is the provision of animproved method for repairing lateral sewer pipe and particularly forrepairing the juncture between the lateral sewer pipe and the mainlinesewer pipe.

A further object of the present invention is the provision of animproved carrier which is integral with the bladder tube, and whichpermits the positioning of the bladder tube within the sewer pipeline inthe general area of the pipeline to be needing repair.

A further object of the present invention is the provision of a methodfor repairing sewer pipeline wherein the outer carrier is disposableafter use.

A further object of the present invention is the provision of animproved method and apparatus for repairing pipeline which is economicalin manufacture, durable in use, and efficient in operation.

SUMMARY OF THE INVENTION

The foregoing objects may be achieved by an elongated bladder tubehaving a fill end for receiving a quantity of fluid resin, a vacuum endfor connection to a vacuum source, and flexible tube walls forming atube cavity therein. A layer of resin absorbent material is within thetube cavity and includes first and second material ends. The firstmaterial end is spaced a predetermined distance from the vacuum end ofthe bladder tube. An elongated wick includes an interior wick endpositioned between the first and second material ends of the resinabsorbent material. The wick extends from its interior wick end towardthe vacuum end of the bladder tube and terminates in a vacuum wick endwith at least a portion of the wick being located between the vacuum endof the bladder tube and the second material end of the resin absorbentmaterial.

One modified form of the above apparatus involves the use of anelongated carrier which is separate from the bladder tube and whichcontains the bladder tube and the tube of resin impregnated material soas to protect them during insertion into a sewer pipeline. When thecarrier is located adjacent the area in the pipeline to be repaired, thebladder tube is inverted out of the carrier tube and this places theresin impregnated material in contact with the sewer pipe walls needingrepair.

Another modified form of the present invention utilizes a carrier whichis integral with the bladder tube, and which is folded back on thebladder tube so as to create an outer carrier tube in protectiverelation over the bladder tube.

The present invention also involves a new method for impregnating acurable resin in a layer of resin absorbent material located within anelongated flexible bladder tube having a fill end and a vacuum endpositioned down stream from the fill end. The bladder tube includes tubewalls forming a tube cavity therein. The layer of resin absorbentmaterial has a down stream end positioned a predetermined distance fromthe vacuum end of the bladder tube and an upstream end. An elongated gasconduit having first and second conduit ends is placed within the tubecavity with the first conduit end positioned upstream from the downstream end of the resin absorbent material and with the second conduitend positioned downstream from the downstream end of the resin absorbentmaterial.

The new method involves introducing a quantity of curable resin into thefill end of the bladder tube, the quantity of resin being sufficient toimpregnant all of the resin absorbent material within the bladder tube.A vacuum source is then connected to the bladder tube at a point spaceddownstream from the downstream end of the resin absorbent materialwhereby the wall of the bladder tube will collapse on the layer of resinabsorbent material and the gas conduit will provide a path forevacuating gas through the collapsed tube walls. Gas is continuouslyevacuated from the bladder tube until the curable resin moves to thedownstream end of the absorbent material and completely impregnates theabsorbent material.

While the gas conduit may take a variety of forms without detractingform the invention, the preferred form is an elongated air permeablewick. However, other forms such as tubes, hoses, or other types ofconduits may be used for evacuating the air and gas through thecollapsed tube walls.

Another aspect of the present invention is the provision of a method forrepairing the junction between a lateral sewer pipe and a mainline sewerpipe. The method involves taking a preliner tube (preferably athermoplastic tube) having first and second ends and being sized to fitwithin the lateral sewer pipe. The preliner tube includes an open cellgasket extending around the interior surface adjacent one end thereof.The open cell gasket is impregnated with an uncured grout. Whiledifferent types of grout may be used without detracting from theinvention, an example of a preferred grout is a chemical hydrophillicgrout manufactured by Thane-Coat Company in Houston, Tex. under theproduct name TC-2400. The preliner tube is then inverted into thelateral sewer pipe to a position wherein the open cell gasketimpregnated with grout is now on the exterior of the preliner andpositioned at the juncture between the lateral sewer pipe and the mainline sewer pipe. The gasket impregnated with grout forms a water tightseal between the preliner tube and the main sewer pipe and the lateralsewer pipe.

Next a flexible sleeve is inserted inside the preliner tube, the sleevebeing impregnated with uncured resin. The sleeve may be made of anymaterial capable of absorbing the uncured resin, but a fabric sleeve ispreferred. Fluid pressure is applied inside the sleeve to force thesleeve radially outwardly against the preliner until the uncured resincures and hardens.

The preferred method for placing the preliner tube in the lateral sewerpipe is by the inversion method described above. Similarly the preferredmethod for inserting the flexible sleeve into the preliner tube is bythe inversion method described above.

Another method for repairing a lateral sewer pipe which joins a mainsewer pipe at a pipe junction involves taking a preliner assemblycomprising a preliner bladder tube and a preliner sleeve within thepreliner bladder tube. The preliner sleeve is impregnated with anuncured first material capable of curing and expanding. While differentmaterials may be used, a preferred material is the chemical hydrophillicgrout referred to above. Next the preliner assembly is inverted into thelateral sewer pipe whereby the preliner sleeve will be outside andsurrounding the preliner bladder tube. A second liner assembly is formedcomprising a second bladder tube and a second sleeve within the secondbladder tube. The second sleeve is impregnated with an uncured secondmaterial capable of curing and hardening. This second material may varywithout detracting from the invention, but it is preferred that acurable resin be used. The second liner assembly is then inverted intothe preliner tube whereby the second sleeve will be outside the secondbladder tube and the preliner bladder tube will be between the prelinersleeve and the second sleeve. The second preliner tube is expandedradially outwardly so as to hold the second sleeve, the preliner tube,and the preliner sleeve against the lateral sewer pipe. The secondsleeve is permitted to cure and harden and then the second bladder tubeis removed. The preliner bladder tube forms a moisture impervious layerbetween the preliner sleeve and the second sleeve. The grout within thepreliner sleeve is forced radially outwardly into any open joints,fractures or holes in the host lateral pipe. The grout is activated bywater and expands and reinforces the waterproof properties of thissystem. Once the procedure is complete the liners protruding within themain line are cut off by using a robotic cutter.

Another method for repairing a lateral sewer pipe which joins a mainsewer pipe at a pipe junction involves forming a main/lateral linerassembly having an elongated main liner tube and an elongated lateralliner tube. The main liner tube has first and second main liner tubeends and the lateral line tube has a first lateral liner tube endconnected to the main liner tube and has a second lateral liner tubeend. The main/lateral liner tube assembly is formed from a felt materialhaving a urethane coat or similar material on its outer surface.

The main liner tube is then impregnated and the lateral liner tube isalso impregnated with an uncured material capable of curing andhardening. The main/lateral liner assembly is then moved through themain sewer pipe to an operative position with the main liner tubeadjacent the pipe junction and with the lateral liner tube extendingwithin the lateral sewer pipe. Next, a lateral bladder tube is insertedinto the lateral liner tube and is spread radially outwardly to pressthe lateral liner tube against the lateral sewer pipe until the uncuredmaterial cures and hardens. Then, a main bladder tube is inserted intothe main liner tube and is spread radially outwardly to press the mainliner tube against the main liner sewer pipe until the uncured materialcures and hardens. The lateral and main bladder tubes are then removedleaving the repaired pipe.

BRIEF DESCRIPTION OF THE FIGURES OF THE DRAWINGS

FIG. 1 is a perspective view of a carrier tube having a bladder tube anda repair sleeve mounted therein.

FIG. 2 is a perspective view of the bladder tube having the repairsleeve therein.

FIG. 3 is a perspective view of the bladder tube of FIG. 2 showing themethod for inserting the resin into the bladder tube.

FIG. 4 is a sectional view taken along line 4—4 of FIG. 2.

FIG. 5 is a sectional view taken along line 5—5 of FIG. 1.

FIG. 6 is a sectional view taken along line 6—6 of FIG. 1.

FIG. 7 is a perspective view of a modified form of the presentinvention.

FIG. 8 is a view similar to FIG. 7, but showing the method of applyingthe resin to the interior of the bladder tube.

FIG. 9 is a sectional view taken along line 9—9 of FIG. 7.

FIG. 10 is a perspective view showing a sewer line to be repaired andshowing the carrier tube inserted therein.

FIG. 11 is a sectional view of the sewer pipe showing the manner inwhich the carrier tube is inserted.

FIG. 12 is a view similar to FIG. 11, and showing the bladder tubepartially inverted,

FIG. 13 is a sectional view similar to FIG. 12, and showing the bladdertube further inverted.

FIG. 14 is a sectional view similar to FIG. 13 and showing thewithdrawing of the bladder tube from the cured repair sleeve.

FIG. 15 is a view similar to FIG. 14 and showing the final removal ofthe bladder tube and the carrier tube with the repair sleeve in place.

FIG. 16 is a sectional view of a lateral pipeline and a main sewerpipeline, and showing a method for repairing the juncture between thetwo.

FIG. 17 is a section view showing the manner in which the preliner ismounted into a bladder tube and a carrier tube.

FIG. 18 is a sectional view of a lateral and main sewer pipe junctionshowing an alternative method for repair.

FIG. 19 is a sectional view of a T-liner assembly which is used in yetanother alternative method for repairing a main lateral sewer pipejunction.

FIG. 20 is a sectional view of a main lateral sewer pipe junction,showing one step in the method for using the T-liner assembly of FIG.19.

FIG. 21 is a sectional view similar to FIG. 20 and showing another stepin the method for using the T-liner assembly of FIG. 19.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to the drawings the numeral 10 generally designates a repairapparatus of the present invention. Apparatus 10 includes a carrierassembly 12, a bladder assembly 14, and a repair sleeve 16 within thebladder assembly 14. Carrier assembly 12 is comprised of a carrier tube17 having a rear end 18 and a forward end 19. An end cap 20 is securedto the rear end 18 of carrier tube 17 by means of clamps 22. Extendingthrough the end cap 20 are a bladder control line 24, a fluid injectionline 26 and an air escape valve 28 (FIG. 6).

At the forward end of carrier tube 17 is a rigid collar 30 (FIG. 5). Apair of end flaps 32, 34 have their rear ends engaging the collar 30 andclamped to the collar 30 by means of clamp 36. Clamp 36 also holds theforward end 19 of carrier tube 17 against the collar 30. Within thecarrier tube is a carrier cavity 38. The attachment of the forward end19 of the carrier tube 17 to the collar 30 is further facilitated bythreads or serrations 40 on the outer surface of collar 30.

The forward ends of end flaps 32, 34 include grommets 42. A pull line 44is threaded through grommets 42 (FIG. 1) and includes a knot 46 whichpermits the line 44 to pull the carrier 12 to the left as viewed in FIG.1. However, when the pull line 44 is pulled to the right, it slips freefrom the grommets 42.

Bladder assembly 14 is shown in FIG. 2 and includes bladder tube 48having a rear end 50 and a forward end 52. Fitted within the rear end 50is a threaded receptacle 54 (FIG. 6) which is held in place inattachment to the rear end 50 by means of clamps 56. A pulling loop 57is also held by clamps 56 and is attached to bladder control line 24 asshown in FIG. 6.

Referring to FIG. 5, within the bladder tube 48 is repair sleeve 16formed of felt or other resin absorbent material. The sleeve 16 isattached at its forward end to an inversion collar 62 by means ofstitches 60. The forward end of inversion collar 62 is fixedly attachedto the forward end 52 of bladder tube 48 by heat sealing, adhesive, orother suitable securing means. The stitches 60 are easily broken away soas to permit the forward end of the repair sleeve 58 to be separatedfrom the rear end of inversion collar 62 by tension forces. A cuff 51 isfolded back at forward end 52 of bladder tube 58 and is secured tocollar 30 by means of a hose clamp 53.

Referring to FIG. 4, a vacuum coupler 64 includes a threaded end adaptedto thread within the threaded receptacle 54 so as to connect a vacuumhose 66 and a vacuum source 68 to the bladder tube 48. A wick 70includes a forward end 72 located forwardly of the rear end 76 of repairsleeve 58. The wick 70 extends rearwardly therefrom to a rear end 74located adjacent the threads of threaded receptacle 54.

The method of impregnating the repair sleeve 58 with resin involvespouring the resin into the forward end 52 of bladder tube 48 asillustrated in FIG. 3. A quantity of resin sufficient to impregnate theentire repair sleeve 58 is poured into the bladder tube. A vacuum isapplied to the vacuum tube 26 so as to cause the bladder tube 48 tocollapse in a flattened state.

The wick 70 provides an important function in this regard since itpermits the gas within the bladder tube 48 to be withdrawn even thoughthe bladder tube 48 is collapsed. The felt or other resin absorbentmaterial of repair sleeve 58 permits gas to be withdrawn, but thissleeve does not permit gas to be withdrawn in the area between the rearend 76 of sleeve 58 and the rear end 50 of the bladder tube 48. The wick70 however, permits the gases to be withdrawn through this particulararea. As a result the flattening of the bladder tube 48 causes the resinto be pressed rearwardly from the forward end until it has completelyimpregnated the felt or other resin absorbent material of repair sleeve58. Rollers (not shown) may also be applied to the flattened bladdertube 48 to facilitate the spread of resin to all portions of repairsleeve 58. The bladder tube 48 is preferably formed of a transparent ortranslucent material which permits visual observation of the progress ofthe resin as it is spread through the repair sleeve 58. By visualinspection it is possible to determine when the resin has spreadcompletely to the rear end 76 of the repair sleeve 58. The vacuumcoupler 64 is then withdrawn from the threaded receptacle 54 and aclosure cap 38 is threaded in its place. During the removal of thevacuum coupler 64, the wick 70 is grasped and pulled out of the bladdertube 48. The wick 70 will have resin impregnated on its inner end, andcan be placed inside the manhole where the repair is taking place as agauge for determining how long it takes for the resin to cure.

After impregnating the repair sleeve 58, the bladder assembly 14 havingthe repair sleeve 16 therein is placed inside the carrier tube 17 asshown in FIG. 1.

As shown in FIG. 10, the repair apparatus 10 is then pulled through asewer line 134 having a area 136 requiring repair. A television camera(not shown) may be placed within the sewer line 134 to show the properlocation for the carrier 10 relative to the area 136 needing to berepaired.

When the carrier tube 17 reaches the position shown in FIG. 11, airpressure, water pressure or other fluid pressure is applied to thecarrier cavity 38. This causes the bladder tube 48 to begin to invertout of the carrier tube 17 in the manner illustrated in FIG. 12. Theinversion of the bladder tube 48 continues until it reaches the positionshown in FIG. 13. In this position the repair sleeve 58 is on theoutside of the bladder tube 48 and is in engagement with the area 136 ofpipe 134 which requires repair. The fluid pressure is continued to beapplied to the inverted bladder tube 48, thereby pressing the bladdertube 48 radially outwardly so as to hold the repair sleeve 58 tightlyagainst the area 136.

The resin is permitted to cure and harden. Then the air pressure isreleased from the carrier tube 17 as shown in FIG. 14 and the bladdercontrol line 24 is pulled to cause the bladder 48 to move to the rightand resume its original uninverted configuration within the carrier tube17. During the withdrawal of the bladder tube 48, the stitches 60 breakaway as to permit separation of inversion collar 62 from repair sleeve58, thereby leaving the hardened repair sleeve 58 in place as shown inFIG. 15.

Referring to FIG. 7 a modified form of the present invention is shownand is designated by the numeral 80. Apparatus 80 includes an outercarrier tube 82 having a rear end 84 which surrounds an end cap 86 andis clamped thereto by means of clamps 88. Extending through end cap 86are a bladder control line 90, a fluid injection line 92, and an airescape valve 94. The outer carrier tube 82 includes a forward end 96 towhich is attached by heat sealing or welding a pair of end flaps 98,100. Flaps 98, 100 are held in place by a spot weld 102 (FIG. 9). A pullcable 104 extends through the grommets 106 in the end flaps 98, 100 andincludes a loop 108 on its end.

A release cable 109 has a spring pin 111 on its end. Spring pin 111 isdetachably retentively retained in loop 108 so as to attach cable 104 toflaps 98, 100. Pulling cable 104 is used to pull the apparatus 80through the sewer line to the desired location. Then release cable 109is pulled and spring pin 111 releases from loop 108, thereby permittingcable 104 to slip through grommets 106 and release its attachment fromflaps 98, 100.

Integrally formed with the outer carrier tube 82 is an inner bladdertube 110 which has a forward end 112 and a rear end 114 adapted toreceive a threaded receptacle 116, clamps 118, and a pulling loop 120. Avacuum line 121 is adapted to connected to the receptacle 116 in thesame fashion shown and described for the modification in FIG. 2.

The juncture between the outer carrier tube 82 and the inner bladdertube 110 comprises a fold 122 where the carrier tube 82 has been foldedback over the bladder tube 110. Initially the bladder tube 110 and thecarrier tube 82 are one continuous tube, and the carrier tube 82 isformed by folding it back over the bladder tube 110.

An inversion collar 128 is spot welded or otherwise attached to theforward end 112 of bladder tube 110 and extends rearwardly therefrom. Atits rear end it is attached to a repair sleeve 124 by means of threads126. The repair sleeve is formed of felt or other material which iscapable of absorbing an uncured resin. Fiber glass, seamless polyesterknit tube, or other materials could be used other than felt or incombination with felt.

Several advantages are obtained by the use of the modified apparatus 80shown in FIGS. 7-9 over the apparatus 10 shown in FIGS. 1-6. Forexample, the apparatus 10 utilizes a rigid collar or clamp 36 at theforward end of the carrier tube 12 in order to connect the bladderassembly 14. This rigid collar can in some situations get caught onoffset sewer pipe joints during installation or in places where the pipeis partially collapsed, and in those situations the carrier sometimesbecomes caught or is unable to pass through the pipe. The rigid collar36 also adds considerable weight to the repair apparatus whereas theapparatus 80 shown in FIGS. 7-9 is light in weight, weighing about onefourth of what the apparatus 10 weighs.

Another advantage of the apparatus 80 is that it eliminates the step ofpulling the bladder assembly 14 into the carrier 12.

The rigid collar 36 used in device 10 must be smaller in diameter thanthe host sewer pipe. This smaller opening makes it harder for the linerto pass through and requires more pressure than the apparatus 80 whichis collapsible and which has a front opening of a size which can be thesame as the host pipe. This makes it easier for the apparatus 80 to passthrough during inversion and requires less pressure.

The apparatus 10 requires different length and diameter carriers for thevarious liners installed. This means that the installer must keep aninventory of carriers that are expensive. The installer must alsotransport more equipment to the job site. The carrier 82 of apparatus 80is disposable and is designed especially for the liner length anddiameter matched to the pipe that is being repaired.

FIG. 8 shows the manner in which the device is filled with resin. Theresin is poured into the forward end of bladder tube 110 while bladdertube 110 is located within the outer carrier tube 82. Carrier tube 82and bladder tube 110 are integral with one another and are preferablyformed of a transparent or translucent material which will permitobservation of the resin as it is poured into the bladder tube 110. Therear end 84 of the carrier tube 82 is folded forwardly as shown in FIG.8 so as to expose the rear end of the bladder tube 110 and permit theattachment and detachment of vacuum tube 121. As the vacuum is applied,a roller (not shown) may be used to roll the bladder tube 110 and thecarrier tube 82 flat and press the resin rearwardly toward the rearwardend of the bladder tube 110. When the fabric liner or repair sleeve 124of bladder tube 110 is fully impregnated, the vacuum tube 121 is removedand a plug similar to the plug 78 is inserted after removal of the wick70. The carrier tube 82 is then unfolded at its rear end and it isattached to the end cap 86 in the manner shown in FIG. 7.

Referring to FIGS. 16-18, a lateral pipeline 138 is shown in a T-jointjunction with a main pipe line 140. The juncture between the two isindicated by the numeral 142. Commonly the junctures between the lateralpipelines and the main pipelines become damaged or destroyed, and resultin ground water infiltrating into the sewer system at the juncture 142.

To repair the lateral pipeline 138, an excavation 137 is made adjacentthe lateral pipeline 138 and a small section of lateral pipeline 138 isremoved to provide access to the interior of lateral pipeline 138. Atube shaped preliner 148 is formed of a moisture impervious materialsuch as polyurethane, polyvinyl chloride, polyethylene or other similarmaterial. An open cell gasket 150 is fused to the outside of preliner148 adjacent one end thereof. Gasket 150 is then impregnated with ahydrophillic chemical grout.

Preliner 148 is then inserted into lateral pipe 138 from the excavation137 by inverting the preliner 148 with air pressure via a launchingdevice such as device 80 shown in FIGS. 7-9. During the inversionprocess preliner 148 is turned inside out and is positioned along thelength of lateral pipe 138 from the excavation 137 to the mainline pipe140. The gasket 150 is positioned so that it is in contact with thejuncture 142 and the area to be repaired.

After the preliner 148 and the open cell gasket 150 are in place, alateral pipe repair sleeve 156 similar to the repair sleeve 124 of FIG.9 is inverted into the interior of the preliner 148. This isaccomplished by placing a carrier such as carrier 80 (FIG. 9) into theopen end of the preliner 148 located within the excavation 137. Thecarrier 80 is placed in the open end of the preliner 148 and the repairsleeve 156 is inverted into the preliner 148 to the position shown inFIG. 16. Preferably the preliner 148 and the gasket 150 protrudeslightly into the hole 146 in the main line 140 so as to permit thehydrophilic grout in the open cell gasket 150 to cure at the damagedjuncture 142 and provide a fluid tight seal in the damaged area. Theground water causes activation of the hydrophillic grout and the groutexpands and cures to provide this seal. This fluid tight seal provides asealing between the exterior of the preliner 148 and the interior of theexisting pipelines 138, 140 at the juncture 142.

After insertion of the preliner 148, a lateral pipeline repair sleeve156 is inverted into the interior of the preliner 148 in the mannershown in FIG. 16. This inversion may be accomplished by the methodsshown in FIGS. 1-15 above. The positioning of the repair sleeve 156 issuch that its lower end protrudes slightly into the hole 146 in the mainline 140 located at the juncture 142 between main pipeline 140 and thelateral pipe line 138. During the inversion process air pressure orfluid pressure is used to cause the bladder tube to expand outwardlyagainst the lateral pipe repair sleeve 156 and the preliner 148 so as tocause them to cure and harden in the position shown in FIG. 16. Duringthis process the grout 150 also cures and expands forming a tight sealat the damaged juncture 142.

The foregoing method for and apparatus for repairing lateral pipelinepermits numerous lateral pipelines to be reconstructed in one day. Theinterior pipeliner 156 is a cured in place liner that is invertedthrough the lateral pipe and will negotiate fittings and bends veryeasily. It will create a watertight seal at the main line and lateralline connection or juncture, and this particular process is compatiblewith the other mainline reconstruction methods described with respect toFIGS. 1-15. The method requires a very small excavation in the yard oreasement of the home or property from which the lateral pipelineextends. The liner is cured at ambient temperatures and does not requirean expensive heating source. The liner is available with a seamlessconstruction design.

After the liners have cured and hardened, the projecting portion 158 istrimmed flush with the inside wall of main pipe line 140 by using aconventional robotic cutter.

Referring to FIG. 18 a modified method for repairing the lateral pipe138 is shown. The preliner 148 shown in FIG. 16 is a thermal plastictube. In the method shown in FIG. 18 a fabric preliner 170 is used. Thefabric preliner is place within a preliner bladder 172 and is invertedinto the lateral pipe 138 in the manner shown in FIG. 18. In thisposition the fabric preliner 170 is in contact with the interior surfaceof the lateral pipe 138. Before the inversion process the fabricpreliner is impregnated with the uncured grout. After it is invertedinto the lateral pipe 138 from the excavation 137, the grout 178 expandsinto the cracks or loose areas of pipe 138 requiring repair. Thepreliner bladder 172 is made of a moisture impervious material and isleft in place after it has been inverted into the lateral pipe 138.

Next a fabric liner 174 is impregnated with a curable resin within aresin bladder 176. The resin bladder 176 is then inverted into theinterior of preliner bladder 172 from the excavation 137 so as toachieve the position shown in FIG. 18 with the resin liner 174 beingpositioned between the resin bladder 176 and the preliner bladder 172.Air is forced into the interior of the resin bladder 176 so as to urgethe fabric preliner 170, preliner bladder 172, and resin liner 174radially outwardly against the interior of lateral pipe 138. After thegrout in preliner 170 activates creating a gel like gasket, the resin inresin liner 174 cures becoming a rigid structural pipe liner. The resinbladder 176 is then removed by pulling on retrieval line 180 and isdiscarded. This leaves the thermal plastic moisture impervious prelinerbladder 172 between the fabric preliner 170 and the resin liner 174 andcreates a barrier between the grout and the resin. It also acts as awater proof jacket for the rigid cured pipe. The fabric preliner 170 haspushed the chemical grout into any open joints, fractures or holes inthe host lateral pipe 138. The water activated grout expands andreinforces the waterproof properties of this system. Once the procedureis complete the protruding liners are cut off in the main line pipe 140by using a robotic cutter commonly known in the art.

Another method for repairing both the main line and the lateral in oneoperation utilizes a T-liner assembly 182 shown in FIGS. 19-21. T-linerassembly 182 includes a main liner sleeve 184 and a lateral liner sleeve186. These sleeves are formed from a material capable of absorbinguncured resin or grout. An example of such a material is felt, but othermaterials may be used. The exterior surface of the main liner sleeve 184and the lateral liner sleeve 186 are coated with urethane or a similarmaterial which will permit them to be protected while being pulledthrough sewer pipes to their desired position. The urethane coating alsoprovides a moisture impervious barrier. The T-liner assembly 182 isformed by cutting the urethane coated felt to a layflat size required tomake a tube approximately 30 inches in length and having a diameterslightly smaller than the interior diameter of the main line host pipeto be repaired. A circular hole is cut in the center of the layflat feltfor accommodating the lateral liner sleeve 186.

Then the lateral liner sleeve is formed from a four or a six inch tubemade of urethane coated felt. The length is dependent upon the distancefrom the main line to the excavation 137. On the end of the lateralliner tube 186 which is going to be connected to the mainliner tube 184,approximately one inch of urethane coating is removed from the exterior.The remaining one inch long section is cut into slits so as to form tabs188 which are inserted into the hole in the main liner tube 184 and arebent back to layflat against the felt. The felt of lateral tube 186 isthen heat welded or otherwise adhered to the felt of the main liner tube184 so as to secure the lateral liner tube 186 to the main liner tube184 in the manner shown in FIG. 19.

Next a urethane collar 190 is slid down over the lateral liner and isfused to the coating on the lateral liner and the main liner by heat orchemical adhesive. This collar provides for an airtight seal between thetwo liners 184, 186. A gasket 192 made of absorbent material such as anopen cell foam or similar material shaped like a donut is then slid downover the lateral liner until it reaches the junction between the lateralliner tube 186 and the main liner tube 184. This gasket will beimpregnated with a hydrophilic chemical grout just prior toinstallation. The grout gasket will provide for a seal between theliners and the main host pipe, thereby eliminating any ground water frominfiltrating into the main line sewer pipe 210. Lateral liner tube 186is provided with a grommet 194 and main liner tube 184 is provided witha grommet 200.

Attached to one end of the main liner tube 184 is a urethane envelope196 having an end cap 205 capable of attachment to a vacuum line (notshown) similarly the other end of the main liner tube 184 is providedwith a urethane e envelope 198 which also includes an end cap 207capable of attachment to a vacuum tube. (not shown).

An inversion bladder similar to the inversion bladder shown in FIGS. 7-9is attached to one end of main line tube 184 by tab strips 202 and iscompletely enclosed within the urethane envelope 198. The bladderassembly includes a carrier tube 206 and a bladder tube 204 which areintegrally formed and which are folded back against one another. An endcap 208 is secured over the interior end of bladder liner 204. Unlikethe carrier tube assembly shown in FIGS. 7-9 however the bladder tube204 does not include a repair collar mounted on its interior.

Before installation into a sewer pipe to be repaired, a hydrophilicchemical grout is impregnated into the grout ring 192, and an uncuredresin is inserted into the upper end of lateral liner sleeve 186. Avacuum is applied first to end tube 205 of urethane envelope 196. Thisdraws the resin inwardly through lateral liner sleeve 186 and throughthe right-hand portion of the main liner sleeve 184 as viewed in FIG.19. Next a vacuum is applied to the envelope 198, and resin is drawninto the left-hand portion of main line liner sleeve 184. The end resultis that the interior felt surfaces of lateral liner 186 and main lineliner 184 are impregnated with the resinous material. When thisimpregnation is complete the urethane envelopes 196, 198 are snipped offwith scissors leaving the remaining assembly of the T-liner assembly 182and the carrier tube 206 and bladder tube 204.

Referring to FIG. 20, a lateral pull line 213 is attached to the grommet194 in liner sleeve 186, and a main pull line 211 is attached to thegrommet 200 in the lateral liner sleeve 186. Line 213 is threadedthrough the sewer line 210 and into the excavation 137. Line 211 isthreaded through a main sewer line 210 and through a lateral sewer line212 into an excavation 137. Line 211 is threaded through the main sewerpipe 210 to an adjacent manhole (not shown

Connected to the end of carrier tube 206 is an end cap 218 having an airline 216 extending therethrough. Also extending through end cap 218 is aretrieval line 215 which is attached to the end cap 208 of bladder tube204 as shown in FIG. 21.

The lines 211 and 213 are simultaneously pulled to bring the liner tubeassembly 182 to the juncture 214 between the main line sewer pipe 210and the lateral line sewer pipe 212. Continued pulling on the lines 211and 213 causes the lateral liner sleeve 186 to be pulled upwardly intothe lateral sewer pipe 212 in the position shown in FIG. 21.

Next, air pressure is provided to the bladder tube 204 to cause it toinvert into the main liner sleeve 184 as shown in FIG. 21. The airpressure holds the main liner tube 184 against the interior of thesurface of the main sewer line 210 so that the resin impregnated withinthe liner sleeve 184 can cure and harden into a cylindrical shape.

Next, another bladder tube assembly is inverted into the lateral linersleeve 186 from the excavation 137. The bladder tube assembly includes abladder tube 220 and a retrieval line 222 which extends through an endcap 224. Continued air pressure provided to the bladder tube 220 forcesit radially outwardly against the lateral liner sleeve 186 until theresin impregnating the lateral liner tube 186 cures and hardens. It alsoforces the grout 192 into the cracks and crevices at the juncturebetween lateral pipe 212 and main line pipe 210 thereby providing awater tight seal to prevent infiltration of ground water into thelateral pipe 212 and the sewer line 210.

After the curing of the grout and the resin within the liner assembly182, the retrieval lines 215, 216 are pulled to remove the bladderassemblies 204 and 220 from the liner sleeves 184, 186 respectively. Theresult is a repaired juncture 214 between the lateral line 212 and themain line

In the drawings and specification there has been set forth a preferredembodiment of the invention, and although specific terms are employed,these are used in a generic and descriptive sense only and not forpurposes of limitation. Changes in the form and the proportion of partsas well as in the substitution of equivalents are contemplated ascircumstances may suggest or render expedient without departing from thespirit or scope of the invention as further defined in the followingclaims.

What is claimed is:
 1. A method for repairing a lateral sewer pipe whichjoins a main sewer at a pipe junction, said method comprising: forming aliner assembly having and elongated main liner tube and an elongatedlateral liner tube, said main liner tube having first and second mainliner tube ends, said lateral liner tube having a first lateral linertube end connected to said main liner tube and having a second lateralliner tube end; impregnating said main liner tube and said lateral linertube with an uncured material capable of curing and hardening; attachinga first line to said first main liner tube end; attaching a second lineto said second end of said lateral liner tube; threading said secondline into said lateral sewer pipe; pulling on said first line to pullsaid main liner tube of said liner assembly to said junction; pulling onsaid second line to pull said lateral liner tube of said liner assemblyinto said sewer pipe; inverting main bladder tube into said main linertube and inverting a lateral bladder tube into said lateral liner tube;inflating said main bladder tube within said main liner tube to spreadsaid main liner tube outward in a radial direction into contact withsaid main sewer pipe; inflating said lateral bladder tube within saidlateral liner tube to spread said lateral liner tube outward in a radialdirection into contact with said lateral sewer pipe; permitting saiduncured material impregnated in said main liner tube and said lateralliner tube to cure and harden; removing said main bladder tube and saidlateral bladder tube from said main liner tube and said lateral linertube respectively.
 2. A method for repairing a lateral sewer pipe whichjoins a lateral main sewer pipe at a pipe junction comprising: forming aliner assembly having an elongated main liner tube and an elongatedlateral liner tube, said main liner tube having first and second mainliner tube ends, said lateral liner tube having a first lateral linertube end connected to said main liner tube and having a second lateralliner tube end; impregnating said main liner tube and said lateral linertube with an uncured material capable of curing and hardening; movingsaid liner assembly to a position within said main sewer pipe whereinsaid main liner tube is located at said pipe juncture and within saidmain sewer pipe and said lateral liner tube is within said lateral sewerpipe; inverting a main bladder tube into said main liner tube andinverting a lateral bladder tube into said lateral liner tube; inflatingsaid main bladder tube within said main liner tube to spread said mainliner tube outward in a radial direction into contact with said mainsewer pipe; inflating said lateral bladder tube within said lateralliner tube to spread said lateral liner tube outward in a radialdirection into contact with said lateral sewer pipe; permitting saiduncured material impregnated in said main liner tube and said lateralliner tube to cure and harden; removing said main bladder tube and saidlateral bladder tube from said main liner tube and said lateral linertube respectively.